British light heavyweight Buatsi earned a win yet underwhelming debut to life under recent management with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's activity level seemingly secured him a majority decision in a competitive 10-round contest at the Co-op Live Arena.
But Parker had his moments, landing some telling clean blows in a fight where the styles never quite clicked, with frequent clinching spoiling the fight.
The officials had it 96-94 for to Buatsi, with the final judge a 95-95.
"It wasn't my greatest showing but what do champions do? They succeed," the victor commented in the ringside as he was faced disapproval from the crowd.
The Londoner bounced back after his first professional defeat - an thrilling contest with Callum Smith in February - to earn a 20th career victory.
Several boxing experts believed Parker, 31, should have been awarded the decision but the Derbyshire fighter experienced the second loss of his 28-match career.
Buatsi Earns Triumph in Dull Match
His career development has stalled in the past few years through promotional disputes and long spells of inactivity.
Once tipped as the next star of the British fight scene, he now finds himself trying to realize his potential - maybe in what appears to be a ultimate opportunity - under new promotional backing.
He opened tentatively, with both competitors prepared to be aggressive in a calculated initial rounds.
Parker, whose single earlier setback came at the lower weight class against John Ryder in two years ago after breaking his hand mid-fight, was making just his second fight at light-heavyweight.
By the fight's midpoint, Parker had stayed in contention, causing problems for the favorite, who operated with a protective stance to narrowly win the cleaner rounds.
The crowd's patience decreased during frequent holding, with Parker going down various instances during close exchanges.
Parker closed well, but multiple periods were hard to judge. However, previous titleholder Carl Frampton - providing analysis for Dazn - had it significantly in favor for Parker, giving Buatsi just one round.
The victor moves on, but with the likes of heavy hitter Benavidez, and Russian star Dmitry Bivol leading the category, the road to world glory - judging by this showing - still appears challenging.
Hatton Memorial Fuels Local Rivalry Fight
In the supporting bout, Arthur overcame Rea by close verdict in a outstanding Manchester vs Manchester fight to win the European light heavyweight title.
The stadium grew hushed for a extremely emotional memorial ahead of the contest as ten bells sounded in remembrance of Manchester's own Hatton, who passed away 46 years old in last month.
It was the initial significant broadcast match card in the city since Hatton's death. As the final chime faded, the quiet gave way to a roar of "there's just one Hatton".
The competition within the ring reflected the emotion. Arthur was knocked down by a significant blow squarely on the face in the early round, rising shakily to his position on the count of eight.
But the red-colored shorts of the fighter soon advanced again. Across the ring, the opponent - in opposing blue - was marked up soon, noticeable damage appearing under his eye as the pair traded hard punches.
Rea, 27, connected with strong blows but the champion, 34, responded in kind with effective uppercuts as the action seldom decreased over the full distance.
Arthur edged the decision with official scores of 114-114, 115-113 and 115-112, but each competitor were persistent and full of heart, all the qualities their hero the legend represented.
